The diesel needs a little more CCA than a standard L/G battery can provide as it runs 15w40 and needs that charge air heater to get started. So, for now have been boosting the battery with a charger or jumping off the 66 MF10G next to it in the shed when it needs starting. I had it started without plugging it in one day when my friends semi was gelled up and the 6.5 turbo diesel next door wouldn't start!

I read about the Honda CRV battery swap and was talking to a friend about it. He knew a guy who had a group 51 Optima yellow top for $60, which I bought last night.

But, it ain't an easy swap for me, see the MF10 Diesel is a '68 and the battery tray is higher up on the pedestal than the 2 73-74 MF12H's in have. Is it a year thing or a hydro vs gear thing with the battery tray? I could take the pedestal off the MF12H parts machine and make it work, but if the right parts are out there it would be easier to just bolt on and go this time of year.

Well, the hydro is out... there are a lot of little changes in the dash tower. And its the whole dash tower that is one part. I would first look to see if you could drill out the welds and lower the tray first.

The sealed "AGM" type batteries like Optimas usually have a higher cranking amp rating than a standard wet cell batt of the same size. It has to do with the way the battery is made, technology. For what you want maybe consider putting the battery at the back of the tractor where the trailer hitch is, this might not be possible if you use the rear lift. If you can put one back there then it can be a big heavy one, lots of starting power and extra weight where you need it.

Well, the hydro is out... there are a lot of little changes in the dash tower. And its the whole dash tower that is one part. I would first look to see if you could drill out the welds and lower the tray first.

I pulled the tower off of the MF12H this afternoon. There will be some mods needed to make it work, but it appears to be easier than using the tower from a MF10G. As for putting it in the back, that isn't going to work either. The tractor has a lift hitch, and a rear light, and I use the drawbar quite often.

The MF12H has a deeper battery tray by 2" or so which is needed as the group 51 is pretty tall. My initial inspection of the variable drive mechanism on the MF10G make me believe only dead space is being put to use. Looks like I'll be firing up the welder this week! Unless a tower comes out of the wood work.

You know... I will back you on it. It can be done with the hydro, but you will need to do a fair amount of fab work to swap over the needed parts from the varridrive set up. You really only have the one bracket on the left that will need to be removed and swapped onto the hydro tower and then you need to make the stud for the varridrive. That could be as simple as a shouldered bolt with some thread one one end removed, and the head and some shoulder on the other end cut down. That could be welded right into the dash tower like that, just drill out a nut to slip over the shoulder side and weld it to the dash tower on the inside for support and to make the needed spacer. Everything else should be the same so with a lot of careful removal from the varridrive tower and measurements, I think it could be an easy enough job. The only thing is you may need to hand make the left side mount for the shaft. If this is set up like I think it is, and you need a hand, I may be able to build one in my shop on the lathe if you need it. I think it's just a simple fitted pipe welded to the dash tower. Although, making it to have a bushing would be the way to rebuild it.

You know... I will back you on it. It can be done with the hydro, but you will need to do a fair amount of fab work to swap over the needed parts from the varridrive set up. You really only have the one bracket on the left that will need to be removed and swapped onto the hydro tower and then you need to make the stud for the varridrive. That could be as simple as a shouldered bolt with some thread one one end removed, and the head and some shoulder on the other end cut down. That could be welded right into the dash tower like that, just drill out a nut to slip over the shoulder side and weld it to the dash tower on the inside for support and to make the needed spacer. Everything else should be the same so with a lot of careful removal from the varridrive tower and measurements, I think it could be an easy enough job. The only thing is you may need to hand make the left side mount for the shaft. If this is set up like I think it is, and you need a hand, I may be able to build one in my shop on the lathe if you need it. I think it's just a simple fitted pipe welded to the dash tower. Although, making it to have a bushing would be the way to rebuild it.

Enjoy, and take photos!

Valid points indeed, I had time to think about it some more last night. Perhaps the easy way to do this is to mark out the cut for the deep style battery tray in the varidrive tower by using the hydro tower as a measuring template. Rather than cutting the tray out of the hydro tower and ruining it. This way I don't have to rebuild the tower, although I could since I have a lathe, milling machine, and a pile of old tools most don't have.

I could then measure a make a template for the "tray" out of oaktag and set it into the newly cut varidrive tower. Then bend a new tray in the vise brake out of .080" mild steel sheet and weld it in. This will give me a new battery tray that isn't all corroded and I still have the original tower for the tractor with the matching patina. I still have a good tower for a Hydra, plus I have a good shallow battery tray to fix another tractor. Maybe if the swap catches on I could start modding the towers and do them on an exchange basis or sell the weld in trays.

One thing to mention, the geometry of the linkages are critical... When I did my rebuild to make a new shaft for the varidrive bracket, the hole was off center just a little bit. However, that was enough to make me loose park, 1st and the set up started in 2nd. I was able to adjust it still, but that is a major change for the tiny bit off that it was.

There are many ways you could attack this and cutting up what you have now and making the battery tray sit lower, may be the easy way to go.